Relevance of gas and particulate phases of tobacco smoke for lung cancer formation: an experimental study in Syrian golden hamsters.

The lower boiling constituents of the gas phase of cigarette smoke such as acrolein, hydrogen cyanide, and formaldehyde are cilia toxic. If such compounds can inhibit the self-purifying capacity of the bronchi and thus act as pacemakers for the action of carcinogens, such as aromatic hydrocarbons, then filtration of these cilia toxic compounds by means of carbon filters should yield protection against the carcinogenic activity of hydrocarbons. To elucidate this hypothesis, benzo(a)pyrene [B(a)P] was instilled intratracheally to Syrian golden hamsters in addition to chronic inhalation of cigarette smoke with and without filtration by carbon filters. Two successive experiments were performed. In both, the yield of pathologic changes in the bronchial system following smoke inhalation with B(a)P instillation was reduced by 40-50% in those groups in which the smoke stream passed through an additional carbon filter compared to the respective groups without carbon filter.